Note: Descriptions are shown in the official language in which they were submitted.
~;~6~0~
Mo-2839
LeA 24,119
POLYAMINES AND A_ ROCESS FOR THEIR PREPARATION
Background of the Invention
_
This invention relates to a simplified one-step
process for the preparation of polyamines containing
primary amino groups.
It is known that aromatic isocyanates can be
converted into primary aromatic amines by acid
hydrolysis.
However, the amine resulting from this
hydrolysis reacts with as yet unreacted isocyanate to
form the corresponding urea thereby decreasing the
amount of product amine. This secondary reaction cannot
be suppressed even by using an excess of stron~ mineral
acids. A recent example of this procedure is described
in JP-P 55 007 829.
It is also known that isocyanates can be
converted into amines by an acid or alkaline catalyzed
reaction, as disclosed9 for example, in N.V. Sidgwick,
The Organic Chemistry of Nitrogen, Clarendon Press,
Oxford, page 236 (1966~ and in J. March, Ad~anced
Organic Chemistry; Reactions 9 Mechanisms and Structure,
McGraw-Hill Book Co., New York, page 658 (1968).
Sidgwick indicates that isocyanate groups can be
hydrolyzed under alkaline conditions but no details of
such a process are disclosed. J. March also speaks in
general terms of the fact that the hydrolysis of
isocyanates and isothiocyanates to amines can be
catalyzed with acids and bases. The occurrence of
isocyanates as intermediate products is also known to
those skilled in the art. For example, isocyanates are
obtained in the course o the Curtius or Lossen
degradation of acid azides and hydroxamic acids and are
decomposed with aqueous acids to form amine salts. A
Mo-2839
procedure of this kind has been described, for example,
in Organic Synthesis, Coll. Vol. IV, 819 (1963) in which
the preparation of putrescine hydrochloride is used as
an example.
E. Mohr, J. prakt. Chem., 71, 133 (1905) was
one of the first to observe that phenyl isocyanate is
more rapidly attacked by dilute sodium hydroxide
solution than by water at low temperatures. C. Naegeli
et al., Helv. Chim. Acta, 21, 1100 (1938) report that
10 when phenyl isocyanates substituted with electron
acceptors (such as nitro groups, halogen atoms or acyl
groups) are hydrolyzed in moist ether or in acetone
containing 1~ of water in the absence of acids or bases,
the corresponding monoamines are obtained in the course
15 of a reaction lasting from several minutes to up to one
hour. From 2,4-dinitrophenyl isocyanate the amine can
even be obtained in hot water without solvent in a
virtually 100% yield and without side reactions leading
to urea formation.
In a process for the preparation of specified
primary aromatic amines containing polyalkylene glycol
ether segments described in DE-B 1,270,046, products
obtained by the reaction of aromatic di- or
triisocyanates with polyalkylene glycol ethers and/or
25 polyalkylene glycol thioethers (preferably those with
molecular weights of from 400 to 4000) are reacted with
secondary or tertiary carbinols and then subjected
(optionally in the presence of acid catalysts) ~o
thermal decomposition at high temperatures in an lnert
30 solvent. One disadvantage of this process, apart from
the high decomposition temperature, is that combustible,
readily volatile alkenes which are explosive when mixed
with air are formed in the course of thermal
decomposition so that appropriate safety measures are
35 r~quired.
Mo-2839
~ ~ 6 ~
DE-B 1,694,152 (US 3,525,871) relates to ~he
preparation of prepolymers containing at least two amino
end groups by the reaction of hydrazine,
aminophenylethylamine or other diamines with an
5 isocyanate prepolymer obtained from a polyether polyol
and polyisocyanate (NCO/NH ratio = 1:1.5 to 1:5). Anv
unreacted amine must be carefully removed in a
subseuuent step of the process because the amine is a
powerful catalyst in the reaction with polyisocyanates
10 and shortens processing ~imes, and may even act as a
reaction component. A similar process is described in
U.S. Patent 3,931,116.
Another method for synthesizing polyamines
containing urethane groups is described in FR-P
15 1,415,317. In this process, isocyanate prepolymers
containing urethane groups are reacted with formic acid
to yield N-formyl derivatives which are saponified to
aromatic amines having amino end groups. The reaction
of isocyanate prepolymers with sulphamic acid according
20 to DE-P 1,155,907 also leads to compounds containing
amino end groups. Relatively high molecular weight
prepolymers containing aliphatic secondary and primary
amino groups may be obtained according to DE-B 1,215,373
by the reaction of relati~ely high molecular weight
25 hydroxyl compounds with ammonia in ~he presence of
catalysts under pressure at elevated temperatures.
According to U.S. 3,044,989 high molecular weight amines
may be obtained by the reaction of relatively high
molecular weight polyhydroxyl compounds with
30 acrylonitrile followed by catalytic hydrogenation.
Relatively high molecular weight compounds containing
amino end groups and urethane end groups may also be
obtained according to DE-A 2,546,536 and U.S. 3,865,791
by the reaction of isocyanate prepolymers with enamines,
Mo-2839
- ~Z60~
~,
aldimines or ketimines containing hydroxyl groups,
followed by hydrolysis. Another method for the
synthesis of aromatic polyamines containing urethane and
ether groups is opening of the ring which occurs in the
5 reaction of isatoic acid anhydride with diols.
Polyamines of this kind have been described, for
example, in U.S. 4,180,644 and DE A 2,019,432,
2,619,840, 2,648,774 and 2,648,825. Aromatic ester
amines obtained by such methods have the disadvantage of
10 being insufficiently reactive for many purposes.
Low reactivity is also found in compounds
containing amino and ester groups obtained according to
U.S. 4,504,648 by the reaction of polyether polyols wi~h
p-aminobenzoic acid ethyl ester and according to EP
15 32,547 by the reaction of polyols with nitrobenzoic acid
chloride followed by reaction of the nitro groups to
amino groups.
The reaction of nitroaryl isocyanates with
polyols followed by reduction of the nitro group to
20 aromatic amine groups is also known (~.S. 2,888,439).
The main disadvantage of ~his process is the high cost
of the reduction stage of the process.
It is also known that certain heteroaromatic
isocyanic acid esters can be converted into
25 heteroaro~atic amines by basic hydrolysis. The
conditions for hydrolysis disclosed by H. John in
J. Prakt. Chemie 1_ , 314 et seq and 332 et seq (1931)
for two quite specific heteroaromatic monoisocyanic acid
esters are, however, both comple~ely unsuitable for the
30 conversion of polyisocyanate compounds into aliphatic
and/or aromatic amines and dangerousO
Applicants' own processes disclosed in DE-A
2,948,419 and 3,039,600 are multistage processes for the
preparation of polyamines by alkaline hydrolysis of
Mo-2839
~ 2 ~ 0~
isocyanate prepolymers using an excess of base (alkali
me~al hydroxides) at low temperatures to form
carbamates, acidification with equivalent or excess
quantities of mineral acids or acid ion exchanger resins
5 accompanied by carbamate decomposition, and optionally
neutralization of excess quantities of acid by means of
bases, followed by isolation of the polyamines.
~ E-OS 3,131,252 discloses a process in which
the carbamates obtained in a first stage by hydrolysis
10 with alkali metal hydroxides are decomposed by
subsequent heat treatment to yield the polyamines.
One-step processes for the production of
polyamines are described in DE-OS 3,223,400 (EP-97,299),
DE-OS 3,223,398 (EP-97,29~) and DE-OS 3,223,397
15 (EP-97,290). In these one-step hydrolysis processes
various solvent-catalyst combinations are employed.
"Ether solvents" are used together with tertiary amines
as catalysts in DE-OS 3,223,400. Polar solvents such as
dimethylformamide are used together with tertiary amines
20 or relatively large quantities of alkali metal
hydroxides, alkali metal silicates or alkali metal
cyanides as catalysts in specified amounts in DE-OS
3,223,398. Carbonates or carboxylates are used in
specified amounts in polar solvents such as DMF in DE-OS
25 3,223,397
All of these processes for the preparation of
polyamines are elaborate and expensive. Even in the
last men~ioned, more simplified methods for the
conversion of polyisocyanates to polyamines, further
~0 simplification would be desirable for obtaining
polyamines even more economically with even better
conversion rates of NCO/NH2 (i.e. higher NH2 numbers) by
an even smoother reaction. A satisfactory process
should have the following advanta~es compared with
35 conventional processes:
Mo-283~
~ 6~ 0
(1) no filtration required;
(2) no separation of a tertiary amine catalyst
by distillation required;
(3) drastic reduction in the quantity of
catalyst (both tertiary amines (according
to DE-OS 3,223,398) and the inorganic,
alkaline compounds such as KOH) required
so that the catalyst could be left in the
polyamine; and
(4) quantitative conversion of NCO into NH2
groups (high NCO/NH conversion rates, i.e.
high amine numbers close to the
theoretical value);
(5) no removal of by-products required; and
(6) simple working up of polyamines and
auxiliary substances.
Summary of the Inven~ion
It has now been found, completely unexpectedly,
that each of the above-listed advantages is obtained by
20 the one-stage hydrolysis of polyisocyanates to
polyamines of the present invention.
This hydrolysis is carried out with a
particular ratio of water to NCO and a particular ratio
by weight of solvent to water using water-soluble
25 carboxylic acid amides as solvents and optionally,
very small quantities of catalyst (no
catalyst is less ~re~erred) under
conditions such ~hat a homogeneous solution is
maintained.
Such optimized conditions make it possible to
use lower temperatures for hydrolysis.
In the process of the present invention, water-
soluble solvents based on carboxylic acid amides,
preferably carboxylic acid dialkylamides or lactams, are
Mo~2839
~ ~ 60 ~1~
employed in order that a substantially homogeneous
solution of the reactants (i.e. isocyanate compounds and
water) and catalyst may be obtained. A particularly
suitable solvent is dimethylformamide and in some cases
5 also dimethylacetamide.
Detailed Description of the Inventio
It is known from DE-AS 1,235,499 that solutions
of isocyanate prepolymers in dimethylformamide may be
converted into highly viscous solutions suitable for
10 spinning elasthane fibers or for coatings by reacting
them with approximately equivalent quantities of water
(80 to 120% of the theoretical amount, where 100%
corresponds to 1/2 mol of water per NCO, i.e. the water
reacts with two hydroxyl equivalents). This reaction is
15 accompanied by chain lengthening via urea groups. The
quite different reaction of isocyanate compounds with
excess quantities of water to form low molecular weight
amines in high yields was unexpected. It was
particularly surprising that this reaction could be
20 carried out in the presence of the catalysts according
to the invention which also accelerate the reaction of
isocyanates with the reaction products formed.
It is also known that isocyanates react with
dialkyl-formamides to form formamidines (H. Ulrich
25 et al, J.Org. Chem., 33, 3928-3930 (1968) and the
literature quoted therein). This reaction does not
interfere with the smooth hydrolysis to polyamines by
the process of the present invention.
One considerable advantage of the process of
30 the present invention is the very low quantities of
catalyst used. Consequently, there is no need to filter
off catalyst or reaction products of the catal~st with
the CO2 liberated in the reaction (e.g. ~OH giving rise
to KHCO3 and K2CO3).
Mo 2839
~ 2 ~0 ~
Since the catalysts useful in the present
invention are readily soluble in the reaction medium,
the problems which occur when using rapidly sedimenting
alkali metal carbonates or bicarbonates (as in the case
5 of DE-OS 3,223,297) do not arise in the practice of the
present invention. Since the catalysts -remain in
solution or are fully miscible, they need not be
filtered off. The catalysts remaining in the amine
product do not normally cause any difficulties due to
10 the small quantities in which they are preferably used.
Since no salts or residues of catalyst need be removed
after the product has been worked up, the process of the
present invention is particularly suitable for the
preparation of highly viscous or solid compounds
15 containing amino groups from which it is very difficult
to remove undissolved residues of salt or catalyst
material.
The catalysts of the present invention are also
particularly suitable for the hydrolysis of isocyanate
20 prepoly~ers based on polyes~ers because under the mild
reaction conditions employed during the hydrolysis
reaction the ester groups are not split off to any
significant extent.
Compared to alkaline hydrolysis processes for
2~ obtaining aminopolyesters from an isocyanate, the
process of the presen~ invention is a significant
improvement.
The catalysts of the present invention are
inexpensive and commercially readily available. They
30 may also be separated from the product and used again
or, in the preferred embodiment, they may be left in the
product. If it is necessary to produce a product which
is completely free from catalyst, the proce~s may even be carried
out without a hot ;nccrporable alkaline and/or metal catalyst
Mo-2839
600~
if the isocyanate, water and solvent are used in
quantities such that the ratios required in the present
invention (especially if the optimum proportion of
solvent to water, the optimum ratio of water to NCO and
5 comparatively high temperatures are used) are satisfied.
The optimum ratios can be determined by a preliminary
experiment. Comparatively high temperatures are used,
preferably in the range of from above 80 to 100C.
Although the conversion rates obtained from such a
10 catalyst-free process are only about 2/3 the rate
obtained with catalyst, they are still very high
(advantageous) compared with those obtained by the
catalyst-free method according to DE-OS 3,223,398. It
is always preferable in the practice of the present
15 invention to work in the presence of catalysts even if
only extremely small quantities of catalysts.
The present invention relates to a single stage
process for the preparation of polyamines containing
primary amino groups by the hydrolysis of compounds
20 containing isocyanate groups (preferably aromatic
-,~x~anate gr~u~s) in media containing water, optionally with the
addition of not incorporable alkaline and/or metal catalysts.
More specifically, the isocyanate groups of organic
compounds containing isocyanate groups, preferably
25 aromatically bound isocyanate groups, based on
isocyanate prepolymers or modified polyisocyanates
having an isocyanate content of from 0.5 to 40 wt.
preferably 1.2 to 25 wt %~ in the c~se of isocyanate
prepolymers and 5 to 20.5 wt.%, preferably 1.5 to
30 10 wt. % in the case of modified polyisocyanates, are
hydrolyzed with 0.75 to 50 mol of water, preferably 1 to
35, more preferably 1.25 to 12 and most preferably 1.5
to 7.5 mol of water per equivalent oE isGcyanate.
This hydrolysis is carried out in the presence
Mo-2839
~1.2~)0~L~
-- 10 -
of O to 1% ~y weight, preferably 0~00005 to 1% by weight
of noL incorporable alkaline and/or metal catalysts,
based on 100% by weight of isocyanate, preferably 0.0001
to 0.099% by weight of an alkaline catalyst, At least
10% by weight of carboxylic acid amides, preferably
carboxylic acid dialkylamides or lactams, most prefer-
ably dimethylformamide or dimethylacetamide, based on
100% by weight of isocyanate are used as solvent in the
hydrolysis mixture. Optionally, 0.1 to 5% by weighL
based on 100% by weight of isocyanate compound, of a
compound containing one or more than one hydroxyl andlor
amino and/or thiol group attached to an aliphatic,
cycloaliphatic or aromatic ~roup may be included. The
solventlwater ratio by weight must be in the range of
3 to 200, preferably 5 to 150, more preferably 10 to 100
and most preferably >Z5 to 75. The hydrolysis mixture
is maintained in a homogeneous reaction phase. The
hydrolysis is carried out at a temperature of 20 to
210C, preferaoly 35 to 165C, more preferably ~0 ~o
150C and most preferably 80 to 130C.
A preferred embodiment of the invention is a
process having the above features in which the iso-
cyanate is hydrolyzed in the presence of 0.0001 to
0.099, preferably 0.002 to 0.08% by weig~t, based on
100% by weight of isocyanate of alkali me~al hydroxides,
alkaline earth metal hydroxides, tetraalkylammonium
hydroxides, alkali metal aluminates, alkali metal
phen~lates, alkali metal thiophenolates, alkali metal
mercaptides, alkali metal hydrogen sulphides, soluble
alkali metal and alkaline earth metal sal~s of (iso)-
(thio~cyanic acids and alkali metal ~-diketone enolates,
andlor 0.0001 to 0.099, preferably 0.002 to 0.08% by
weight, based on 100% by weight of isocyanate of
carbonates or bicarbonates of alkali metals, and/or
Mo-283~
6~0~
-- 1 1 -
0.0001 to 0.099, preferably 0.0001 to 0.0099, more
preferably 0.0002 t.o 0.008% by weight of alkali metal
and alkaline earth metal salts of organic carboxylic
acids including salts of formic acid as ~he alkaline
catalyst. In an even more preferred embodiment the
isocyanate is hydrolyzed with 1.25 to 12, preferably 1.5
to 7.5 mol of water per isocyanate equivalent using one
of the above-listed not incorporable alkaline catalysts
in the specified quantities while maintaining a carboxy-
lic acid amide (preferably dimethylformamide/water)
ratio by weight in the range of >10 to 150, preferably
>25 to 75 at temperatures of 35 to 165C~ preferably 80
to 130C.
In another embodiment of the process of the present
invention the isocyanate is hydrolyzed in the presence
of 0.0001 to 0.99% by weigh~, preferably 0.001 to 0.099%
by weight of tertiary amino compounds (based on 100~/. by
weight of isocyanate compound) using a water/NC0 ratio
of from 1 to 7.5 mol of water per NC0 equivalent and a
dialkyl carboxylic acid amide (preferably dimethylform-
amidelwater) ratio by weight in the range of >10 to 150,
preferably >25 to 75, at a temperature of 35 to 165C.
It is particularly preferred tha~ this process be
carried out in the presence of 0.0001 to 0.099% by
weight of ~ertiary amine compounds using a water/NC0
ratio of 1 to 24 mol of wa~er per NCO eq~ivalent and a
dialkyl carboxylic acid amide/water (preferably
dimethylformamide/water~ ratio by weight of >10 to 50
at a tempera~ure of 35 ~o 165C.
In another, less preferred embodiment of the
invention, the isocyanate is hydroly2ed in the presence
of 0.0001 Lo 0.0099, preferably 0.002 to 0.008~/. by
weight of metal catalysts with preferably 1.5 to 7.5 mol
of water per isocyanate equivalent while main~aining a
Mo-2839
o~
- lZ -
carboxyliL acid dialkylamide/water (preferably dime~hyl-
formamide/water) ratio by weight of ~10 to S0, pre-
ferably >Z5 to 50, at tempera~ures of 25 ~o 165C.
In the process of the present invention, the iso-
cyanate may be hydrolyzed wiLhou~ a catalyst using a
wa~er/isocyanate ratio of 1 to 25 mol of water per i50-
cyanate equivalent and a carboxylic acid dialkylamide/
wa~er (preferably dimethylformamide/water) ratio by
weight of >lC to 50, preferably >25 to 50, at Lempera-
Lures of 35 Lo 165C, optionally under pressure.
The catalysts used in the inventive process have
to be no~ incorporable, which mean that ~hey do no~ have
any groups which can reac~ with NC0 groups.
In ~he various embodiments of ~he present inven-
tion, ~he isocyanate compound is preferably an isocyan-
a~e prepolymer having an isocyanate conten~ of from 1,5
to 10 wt.% or a modified polyisocyana~e, in particular
a ure~hane-modified polyisocyanate having an isocyana~e
content of from 1.5 to 20.5 wt.%, in particular 5 to
20.5 wt.%. Neu~ral salts may be included in thP hydroly-
sis mixture. It is preferred to use 1 ~o 35 mols of
wa~er, in par~icular l.Z5 to 12 mols of wa~er per equi-
valen~ of isocyana~e.
The solven~ is pre~erably dim0~hyl~0rmamide used
in quantities of 100 to 1000/. by weight, based on 100%
by weight of isocyanate compound.
Hydrolysis is preferably carried ouL a~ tempera-
tures from 40 to 150~C, most preferably aL 80 ~o 130C
and preferably withou~ excess pressure. The solids con-
cen~ra~ion of the reaction mixture subjec~ed ~o hydroly-
sis is generally from 20 to 75 wt.%, preferably 25 to
~5 60 wt.%, mos~ preferahly 30 to 55 w~.%, Al~hough even
lower sulids concentrations may be employed, this is
less advantageous for practical reasons ~e.~. solven~
recovery).
Mo-2839
~L2~QO~l~
- 13
The isocyanate hydrolyzed is preferably an
isccyanate prepolymer conta~ing frornO.5 to 40 wt.%, preferably
1.2 to 25 wt.%, more preferably from 1.5 to 10 wt.% of aromatically
bound isocyanate groups and based on relatively high
5 molecular weight, difunctional or higher functional
polyether, polyester, polycaprolactone and/or
polycarbonate polyols and diisocyanates or
polyisocyanates modified with low molecular weight diols
or polyols (molecular weight up to 399) and containing
10 1.5 to 20.5 wt. ~, preferably 5 to 20.5 wt. ~ of NCO.
The invention also relates to the polyamines
obtained by the process according to the invention,
particularly those containing 0.46 to 9.52 wt. % of
primary, preferably aromatically bound NH2 groupsO
The present invention further relates to the
use of the polyamines obtained by the process of the
present invention for the preparation of optionally
cellular polyurethane(urea)s by reaction with a
polyisocyanate and optionally other compounds containin~
20 isocyanate reactive groups, optionally in the presence
of known auxiliary agents and additives and/or solvents.
According to the invention, a compound
containing 1, 2 or more hydroxyl and/or amino and/or
thiol groups bound to aliphatic, cycloaliphatic or
25 aromatic groups may be added in minor quantities (i.e.
0.1 to 5 % for every 100 % of isocyanates). The
addition of these compounds containin~ "H-active groups"
is advantageous because polyamines virtually free from
monomeric polyamines may be obtained from isocyanate
30 compounds containing low molecular weight
polyisocyanates (e.g. isocyanate semiprepolymers)
without treatment of the isocyanate compounds by thin
layer evaporation or s:imilar processes. Modified
polyamines which contain various segments linked through
Mo-2839
2 ~
- ~4 ~
urethane groups, thiourethane groups or urea groups can
thus be obtained quite simply and without an additional
reaction step.
A trifunctional or higher functional polyamine
5 can therefore be obtained from a difunctional isocyanate
compound by using a trifunctional or higher functional
compound containing "H active groups" in the isocyanate
hydrolysis process.
The isocyanate compounds used in the process of
10 the present invention contain two or more aromatic,
heterocyclic and/or aliphatic (preferably aromatic)
isocyanate groups. These isocyanates include modified
polyisocyana~es of the type obtained by partial
conversion of isocyanate groups into urethane, urea,
15 biuret, uretdione, isocyanurate and/or uretoneimine
groups and isocyanate prepolymers obtained by the
reaction of polyvalent compounds in the molecular weight
range of 62 to 129000 (prPferably 400 to 6,000)
containing isocyanate reactive H groups with (excess)
20 quantities of aromatic polyisocyanates and (less
preferred) semi-prepolymers made up of isocyanate
prepolymers and additional low molecular weight
polyisocyanates.
Examples of modified aromatic polyisocyanates
25 useful in the present invention include:
polyisocyanates containing urethane groups (obtained by
modification with low molecular weight polyols); poly-
isocyanates con~aining urea groups (e.g. by modi~ication
with water, DE-P 1,230,778); polyisocyanates containing
30 biuret groups (U.S. 3,124,605 and 3,201,372, GB-P
889,050); polyisocyanates containing isocyanurate groups
(DE-PS 1,022,789 and 1,222,067) and dimeric and
oligomeric polyisocyanates containing uretdione or
uretoneimine groups. These are known compounds or are
Mo-2839
2 ~
obtainable by known processes. Several such uretdione
polyisocyanates are mentioned in Analytical Chemistry of
the Polyurethanes, Volume 16/III, High-Polymers-Series
(Wiley 1969).
Such modified polyisocyanates containing
urethane and/or urea and/or biuret and/or uretdione
and/or isocyanurate and/or uretoneimine groups suitable
for the process of the present invention generally have
an isocyanate content of from 1.5 to 40 wt. %,
10 preferably from 10 to 25 wt. %. Polyisocyanates
containing urethane groups ~by modification with low
molecular weight (molecular weight 62 to 399) diols
and/or polyols) and having isocyanate contents of from
>1.5 ~o 20.5 w~. %, preferably 5 to 20.5 wt. ~ are
15 particularly preferred.
The most important isocyanate compounds useful
in the process according to the invention are isocyanate
prepolymers of the kind obtained in a known manner by
the reaction of low molecular weight and/or relatively
20 high molecular weight compounds containing hydroxyl
and/or amino and/or thiol groups as reactive groups
(molecular weight 62 to about 12~000) with an excess of
polyisocyanate.
The polyisocyanates used for the preparation of
25 the compounds containîng free isocyanate groups may in
principle be any aromatic, aliphatic or heterocyclic di-
or polyisocyanates of the kind described, for example,
by W. Siefken in Justus Liebigs Annalen der Che~ie, 562,
pages 75-136 (1949) and ~hose known in the art which are
30 men~ioned on pages 12 1:0 23 of DE-OS 3,223,397. Low
molecular weight and/or relatively high molecular weight
compounds having molecular weights of 32 and 60-12,000
containing hydroxyl and/or amino and/or thiol groups as
reactive groups suitable for the preparation of
Mo-2B39
~o~
16 -
prepolymers and modified isocyanates are also described
in these disclosures.
Isocyanate prepolymers which have been obtained
from relatively high molecular weight polyols (molecular
5 weight of 400 to 12,000), preferably polyether polyols,
optionally together with chain lengthening agents o the
type described above (molecular weight 62 to 399) by a
reaction with aromatic diisocyanates in an equivalent
ratio of 1:1.5 to 1:2.8 (in particular about 1:1.5 to
10 1:2) are preferred for the process according to the
invention.
The isocyanate content of the isocyanate
prepolymers used in the process amounts to 0.5 to 30
wt. Z, preferably 1.2 to 25 wt~ %, in particular 1.5 to
15 10 wt. % with functionalities of 2 to 8, preferably 2 to
4 and most preferably 2 to 3.
So-called "semiprepolymers", i.e. mixtures of
isocyanate prepolymers or modified polyisocyanates with
other free polyisocyanates which may ha~e an even higher
20 isocyanate content, e.g. up to 40 wt. %, may also be
used in the process of the present invention. For
practical and economic reasons, however, the use of
these semiprepolymers is in most cases not advisable.
The monomeric amine contents formed from the monomeric
25 polyisocyanate components are liable to interfere with
numerous applications.
In the form of their modified isocyanates (in
most cases free from urethane groups~ or in the form of
their "semiprepolymers" or isocyanate prepolymers
30 (containing urethane groups), the compounds containing
free isocyanate groups have a total isocyanate group
content within the range of 0.5 to 40 w~. X, preferably
1.2 to 25 wt. % and most preferably 1.5 to lO wt. ~.
Mo-2839
- 17 -
Water i9 used as a reaction component,
preferably in liquid form. In order to achieve
substantial conversion of the isocyanate groups into NH2
groups, it is necessary to use at least one
5 mol of water per equi~7alent of ~co.
If substantially less than 1 mol (in particular
<0.75 mol) of water is used, then prelengthening with
10 urea formation preferentially takes place. On the other
hand, it has surprisingly been found that the use of a
very large excess of water also leads to relatively high
proportions of unwanted prelengthened products. This
also occurs if the reaction mixture is monophasic. It
15 has been found tha~ the optimum quantity of water
depends not only on the quantity of isocyanate groups to
be converted but also on the quantity of solvent used.
This means that the quantity of water used for
one equivalent of isocyanate is ~ 0.75 mol of
20 water, preferably ~0.75 to 50 mol of water, more
preferably 1 to 35 mol of water, most preferably 1,25 to
12 mol of water. If, for example, a bifunctional
isocyanate prepolymer with T 100 ~= 2,4-tolylene
diisocyanate) having an isocyanate content of 3.6~ is
25 used, then the equivalent weight o isocyanate groups is
about 1167. This means that 313.5 g of water,
preferably 13.5-900 g, more preferably 18-630 g, and
most preferably 22.5-216 g of water are used for about
1167 g of this prepolyrner. The lower limit of water in
30 this process is 0.75 mol of water, in most cases l mol
of water and can be combined with the upper limits in
any manner desired.
According to the invention, howe~er, the
water/NCO ratio claimed must be used in conjunction with
Mo-2839
6~
- 18 -
certain proportions by wei~ht of solvent to water.
These proportions by weight range from 3:1 to 200:1 but
are preferably in the region of 5:1 to 150:1, especially
from ~10:1 to 100:1, the optimum range being in most
5 cases from ~25:1 to 75:1.
This means that, for example, based on 1000 g
of solvent (preferably dimethylformamide), the quantity
of water used is in the range of 5 to 333 g.
It has been found ~hat if the other conditions
10 according to the invention are also observed, in
particular if a relatively high proportion of solvent is
used in the solvent/wa~er mixture (in particular a
dimethylformamide/water mixture), a particularly
advantageous NCO/NH2 conversion rate is obtained and
15 that the quantities of catalyst used may be minimal.
If the absolute quan~ity of water required is
used and the more advantageous solvent/water ra~io is
observed, the quantity of solvent is such that more than
10 % by weiaht, preferably ~ 1~0 % and most preferably us to
1000 ~ of solvents are used for 1~0 ~ by weight
isocyanate component. It has been found that the
minimum quantity of solvent required for achieving
complete NCO/NH2 conversions depends upon the reaction
temperature. The higher the reaction temperature, the
25 lower may be the quantity of solvent used. The quanti~y
of water required (based on NCO~ is largely unaffected
by ~hese factors.
If necessary, experiments may be carried out to
determine the optimum ratios of NCO equivalents, water
30 and solvent for a particular isocyanate component within
the general framework indica~ed.
Alkaline and/or metal catalysts havin~ no NCO reactive
groups may ~e used in the present invention. mese compounds are
capable of raismg the NH number of the amines in the product to a
Mo-2839
2 ~
- 19 -
level above that obtainable without the use of
catalysts.
The catalysts used may be solid or liquid but
must be sufficiently soluble, preferably completely
5 sGluble in the reaction mlxture. Based on 100 ~ by weight of
isocyanate component, the catalyst is generally used in
a ~uantity of 0.00005-1 % by ~eight. Different types of
catalyst have different preferred ranges of quantities.
The quantity of catalyst required is also dependent on
10 the solvent/water ratio. The catalyst requirement is
least when the optimum solvent/water ratio is employed,
but even then a certain surprisingly small amount of
catalyst, is required for producing the highest possible
NCO/NH2 conversion rates. Even if the water/solvent
15 ratio is not quite optimal, good results can still be
obtained by increasing the quantity of catalyst. The
quantity of catalyst required for complete conversion of
NCO groups into NH2 groups also depends upon the
reaction temperature. It is found that this quantity
20 should be higher at lower temperatures, e.~. l.5C, than
at a higher reaction temperature, e.g. at 100C. If the
amine yield is incomplete when a given quantity of
catalyst is used, the yield may be increased by
increasing the reaction temperature.
Basic inorganic and organic salts and in
particular hydroxides (particularly preferred group) may
be used as catalysts. These include salts of strong
organic or inorganic bases with weak inorganic or
organic acids which give an alkaline reaction in water.
30 Specific examples of such ca~alysts include: hydroxides
of alkali metals and alkaline earth metals and
tetraalkylammonium hydroxides (in particular NaOH and
KOH) and soluble aluminates (such as sodium aluminate);
carbonates of alkali metals, in particular sodium
Mo-2839
-```` ~1.26~
20 -
carbonate and potash; bicarbonates of alkali metals, in
particular sodium and potassium bicarbonate; alkali
metal and alkaline earth metals ~alts of mono and
polycarboxylic acids free from isocyanate reactive
5 groups, including the salts of formic acid (pre~erably
salts of monocarboxylic acids containing up to 18 carbon
atoms) such as sodium formate, sodium acetate, potassium
octoate and potassium stearate; alkali metal salts o~
phenols and thiophenols optionally substituted with
10 groups which are unreactive with NCO; soluble alkali
metal and alkaline earth metal salts of weak acids such
as cyanic acid, isocyanic acid, thiocyanic acid,
isothiocyanic acid, silicic acid, phosphorus-III- to -V-
acids, hydrocyanic acid, hydrazoic acid, etc.; alkali
15 metal mercaptides and sulphides and hydrogen(poly)-
sulphides; and ~-diketone compounds such as sodium,
potassium or magnesium acetylacetonates and
acetoacetates. Tertiary amines may also be used as
catalysts but they are less pre~erred. The tertiary
20 amines used preferably have an aliphatic or
cycloaliphatic structure, and mixtures of various
tertiary amines may be used. Examples include compounds
which are not completely water-soluble, e.g. the
trialkylamines such as trimethylamine, triethylamine,
25 tripropylamine, triisopropylamine, dimethyl-n-propyl-
amine, tri-n-butylamine, tri-isobutyl-amine, tri-iso-
pentylamine, dimethylbutylamine, triamylamine, trioctyl-
hexylamine, dodecyldimethylamine, dimethylcyclohexyl-
amine, dibutylcyclohexylamine, dicyclohexylethyLamine,
30 tetramethyl-1,3-butane-diamine; and tertiary amines
containing an araliphatic group, such as
dimethylbenzylamine, diethylbenzylamine and
-methylbenzyldimethylamine. Trialkylamines having a
total of 6 to 15 carbon atoms in all the alkyl groups
35 (e.g. triethyl- to triamyl-amine and dimethylcyclohexyl-
Mo-2839
amine) are preerred.
Suitable tertiary amines apart from the
trialkylamines also include those which have an
additional tertiary amino group or an ether group, in
5 particular in the ~-posi~ion to the tertiary group.
Examples include dialkylaminoalkyl ethers and
bis-dialkylaminoalkyl ethers (US 3,330,782, DE-B
1~030,558), e.g. dimethyl-(2-ethoxyethyl)-amine,
diethyl-~2-methoxypropyl)-amine, bis-(2-dimethyl-
lO aminoethyl)-ether, bis-(2-diethylaminoethyl)-ether,
bis-(2-diethylaminoisopropyl)-ether, 1-ethoxy-2-
dimethyl-aminoethoxyethane, N-methyl-morpholine,
N-ethyl-morpholine and N-butyl morpholine; also,
permethylated polyalkylene diamines such as
15 tetramethylethylenediamine, tetramethyl-1,2-
propylenediamine, pentamethyldiethylenetriamine,
hexamethyl-triethylenetriamine and higher permethylated
homologs (DE-A 2,624,527 and 2,624,528); also, diethyl-
aminoethyl-piperidine, 1,4-diaza-(2 9 2,2)-bicyclooctane,
20 N,N'-dimethylpiperazine, N,N'-diethylpiperazine,
N-methyl-N'~dimethylaminoethylpiperazine,
N,N'-bis-dimethylaminoethylpiperazine, N!N'-bis-
dimethylaminopropylpiperazine and other bis-dialkyl-
aminoalkylpiperazines (mentioned e.g., in DE-A
25 2,636,787).
Preferred representatives of this group are the
water-soluble compounds such as tetramethylenediamine,
permethylated diethylenetriamine, N-methyl-morpholine,
bis-2-dimethylaminoethylether and N-methylpiperidine.
Acylated tertiary amine derivatives such as
l-dimethylamino-3-formylaminopropane, N-(2-dimethyl-
aminoethyl)-propionamide), N-(2-diethylamino-
ethyl)-benzamide and other tertiary amines containing
amide groups (preferably formamide groups) according to
35 DE-A 2,523,633 and 2,732,292 may also be used.
Mo-2839
6~
- 22 -
Tertiary amines of the pyridine series and
~ertiary amines containing at least one aromatic group
attached to ~he nitrogen atom are also effective, e.g.
dimethylaniline.
If the tertiary amines are not soluble in
water, their boiling point should be below 250C,
preferably below 200C.
Metal catalysts may also be used in the present
invention but they are not preferred.
The polyvalent metal compounds described in the
literature as catalysts for isocyanate chemistry may be
used in the process according to the in~ention. These
are preferably compounds of tin, zinc or lead, such as
dibutyl tin dilaurate, tin octoate, zinc acetyl
15 acetonate and lead octoate. These are on the whole less
preferred.
The solvent component may be an aromatic,
aliphatic or cycloaliphatic carboxylic acid amide which
is at least partly, preferably completely
20 water-miscible/water-soluble and has 1 10 carbon atoms
in the acid moiety, e,g. dimethylformamide (DMF),
formamide, diethylformamide, dime~hylacetamide,
dimethylpropionic acid amide, benzoic acid dimethylamide
and N-methylpyrrolidone. Carboxylic acid dialkylamides
25 are preferred, in particular dimethylformamide.
The solvent ~ay contain up to 75 wt. % of other
aprotic dipolar solvents such as: water-soluble,
tetraalkylated aliphatic ureas having 4 to 12 carbon
atoms, e.g. tetramethylurea or tetraethylurea;
30 water-soluble, aliphatic or cycloaliphatic sulphones or
sulphoxides having 2 ~o 10 carbon atoms, e.g.
tetramethylsulphone or dimethylsulphoxide; and
water-soluble aliphatic or cycloaliphatic phosphoric
acid amides, e.g. hexamethylphosphoric acid triamide.
Mo-2839
O~L~
- ~3 -
These op~ional solvents may be mixed in any
proportions. Among these optional solvents, it is
preferred to use those which uncler normal pressure boil
at 56 to 250C, preferably 64 to 165C because this
5 simplifies the working up process.
Solvents which are not completely miscible with
water, such as propionitrile, methyl ethyl ketone, ethyl
acetate or hydrocarbons may be used in minor quantities
but the addition of such solvents is not preferred. It
lO is preferred to use DMF as the only solvent.
The following limiting conditions of the
process apply to the quantities (in particular the upper
limits) of solvents to be used:
1. ~10, preferably 100 to 1000 % by weight of
15 solvent should Le used per 100 ~ ~y weight of isocyanate compound
n the reaction mixture for hydrolysis.
2. Sufficient water and optionally solvent
should be used to produce a substantially homogeneous
(at the most slightly cloudy) or preferably completely
20 homogeneous, clear solution with the isocyanate compound
at the reaction temperatures. It is particularly
preferred to use sufficient water to form a monophasic
mixture at all temperatures of the process but always
within the ratio of solvent (~MF):water and of water:
25 NCO component mentioned above.
The catalytically active compounds are
generally added to the solvents and water. They may in
some cases be added to the co~pound containing
isocyanate groups but this is not preferred.
To hydrolyze the NCO compounds to polyamines
with a sufficiently high amine number (high conversion
rate), it is advantageous to maintain a concentration of
NCO compound of< 75, preferably< 55 wt % in the reaction
mixture.
Mo-2839
v~
- 24 -
The degree of dilution is limited by the
economics of the working up process and would in
practice be in the region of a 3% solution.
However, it is necessary to use at least
5 sufficient solvent wi~hin the above-mentioned ratios of
the quantities of water, solvent and isocyanate to
ensure that the reaction mixture remains substantially
homogeneous, preferably completely homogeneous.
According to a less preferred embodiment of the
10 process, compounds containing "H-active groups" and
having two or more hydroxyl, amino and/or thiol groups
may be added to the reaction mixture Such compounds
have already been mentioned as starting components for
the isocyanate compounds used in the process according
15 to the invention and are most preferably difunctional to
optionally tetrafunctional compounds in the molecular
weight range of 62 to 2000. Compounds of this type
containing at least two primary hydroxyl groups, e.g.
ethanediol, butanediol, propanediol, polyethylene
20 glycols, trimethylol-propane or the like are preferred.
~ompounds containing different "H-active groups" may, of
course, also be used, e.g. aminoalkanols.
Compounds containing only one H-active group
~ay be used as monofunctional chain breaking agents.
25 Methanol, e~hanol, cyclohexanol, cyclohexylamine,
aniline or asymmetric dimethylhydrazine are examples of
such agents.
The prelengthening reaction, i.e. the reaction
of isocyanate with already formed amine to undergo chain
30 linking and form ureas, may occur as a side reaction of
the process according to the invention. This side
reaction can to a large extent be suppressed by carrying
out the process in dilute solution, using catalysts and
solvents in accordance with the invention and by
Mo-2839
~Z6~0~
- 25 -
maintaining relatively high reaction temperatures, e.g.
80 to 130C. Although it is preferred to keep these
side reactions down as much as possible, it may be
permissible on economic grounds to accept a certain
5 degree of prelengthening.
If the process parameters are sufficiently
accurately observed, however, the method according to
the invention enables the isocyanate groups to be
virtually completely converted into NH2 groups.
The reaction according to the invention is
preferably carried out in a homogeneous phase. Slight
cloudiness of the reaction mixture may temporarily occur
if the starting materials ~re incompletely dissolved due
to the presence of slightly too much water or too much
15 isocyanate compound.
The presence of a multiphase mixture due to ~he
addition of an excessive quantity of water and
precipitation of the isocyanate prepolymer, however,
results in unsatisfactory products. The optimum
20 proportions in which the starting components should be
mixed in order that homogeneous mixtures may be obtained
within the required proportions may be determined by a
few preliminary tests.
As already men~ioned above, the reaction may be
25 carried out at temperatures from 20 to 210C. It is
preferred, however, to employ temperatures in thè range
of 35 to 165C, in particular from 80 to 130~C because
this results in the best volume/time yields combined
with high solubility and, surprisingly, the least amount
30 of urea lengthening. In special circumstances, it may
be necessary to carry out the reaction under pressure in
order that su~ficiently high temperatures may be
obtained.
~o-2839
- 26 -
The onset of the reaction ~lay be recognized by
the almost spontaneous liberation of CO2, which is
observed to take place even at low temperatures, e.g.
10C. It is however much more advantageous for the
5 purpose of the invention to employ higher temperatures
in order to suppress urea formation. It is important to
ensuxe thorough and rapid mixing o the reactants to
form a homogeneous solution. This may be achieved
mainly by using solvents. The reduction in viscosity
10 obtained when elevated reaction temperatures are
employed operates in the same direction. The reaction
may be carried out batchwise or continuously.
The information disclosed in DE-OS 3,223,397,
page 32, line 20 to page 35, line 10 applies both to the
15 continuous and the batchwise embodiments.
Working up of the end product may also be
carried out continuously or batchwise. The reaction
mixture is normally worked up by dis~illation,
extraction or phase separation or a combination of these
20 methods. ~xtraction processes, optionally after
dilution with water, may be carried out with solvents
which are insoluble in water, such as methylene chloride
or chlorobenzene, but these methods are not pre~erred.
Phase separation of the reaction mixture by
25 cooling occurs in some cases if hydrolysis has been
carried out at relative~y high temperatures and in the
presence of a relatively large quantity of water at the
limit of solubility. Phase separation may be improved
or indeed achieved by the addition of water. The
30 aqueous phase optionally containing solvent and in most
cases also catalyst is separated from the polyamine
phase. The aqueous phase is then in most cases ready
for reuse.
Mo-2839
'~L26
27
The polyamine phase may contain residues of
catalyst, some water and possibly solvent in addition to
the polyamin~. These are removed as completely as
possible by distillation, if necessary with application
5 of a vacuum or by thin layer distillation.
If the compound containing isocyanate groups
still contains free (i.e. monomeric) isocyanate due to
the method employed for its preparation, the monomeric
amine formed from this monomeric isocyanate may in some
10 cases accumulate in signif~cant quantities in the
water/solvent phase if the product is worked up by phase
separation. The polyamine obtained by this simple
method of working up is then virtually free from
monomers. It may however be advisable to free the
15 solvent phase as much as possible from monomeric amine
by working it up before it is used again.
The reaction mixture is preferably worked up
without phase separation by distilling of the solvent
or solventtwater mixture after termination of the
20 reaction (no more evolution of CO2 observed)O
Distillation is preferably carried out in a vacuum (e.g.
at l to 700 Torr) although an even higher vacuum (e.g.
0.001 to 1 Torr) may be applied or the removal of
volatile residues. It has been found advantageous to
25 start wi~h a temperature in the region of about 60 -
100C and subsequently to raise the temperature to 80 -
lOnC. The solvent which is distilled off may be used
again several times.
The polyamin~s obtained by the process of the
30 invention after the working up process are generally
colorless to slightly colored, medium viscosity to high
viscosity and in some cases relatively high melting
products having an amino group content of from 0.19 to
15.23 wt. %. These polyamines may also contain groups
Mo-2839
~ ~6~V~
- 28 -
which were already present in the starting materials
from which they were produced such as urethane and/or
urea and/or uretdione and/or isocyanurate and/or biuret
groups and/or uretoneimine groups and optionally ~ther
5 and/or acetal and/or carbonate and/or ester and/or
thioether and/or dialkylsiloxane groups and/or the
groups of polybutadienes. Additional linkages may be
formed by side reactions. For example, urea groups may
be formed from the ~lready saponified portions and
10 remaining isocyanate groups in the course of hydrolysis.
The quantity of primary aromatic amino groups present in
the polyamines is at the most equal to the quantity of
isocyanate groups present in the isocyanate compounds,
i.e. about 0.19 to 15.23 wt. X of NH2 (when the
15 isocyanate content was 0~5 to 40 w~. %), preferably 0.46
to 9.52 wt. ~ NH2 (NCO content of 1.2 to 25 wt. Z) and
most preferably 0.58 to 3.81 wt. % NH2 ~NC0 content of
1.5 to 10 wt. %).
In view of their low vapor pressure, the
20 polyamines of the present invention, which are
preferably aromatic, are advantageously used as
reactants for blocked or free polyisocyanates in the
production of polyurethanes (polyurethane ureas),
cellular or non-cellular polyurethane plastics or
25 polyurethane foams. These amines may also be combined
with other, low molecular weight (molecular weight 32 to
399) and/or relatively high molecular weight (molecular
weight 400 to about 12,000) compounds containing
isocyanate reacti~e groups. Suitable starting
30 components for the production of polyurethanes by known
processes are mentioned above in connec~ion with the
preparation of the prepolymers as well as in DE-A
2,302,564, DE-A 2,432,764 (U.S. 3,903,679) and DE-A
2,639,0~3, 2,512,385, 2,513,815, 2,550,7g6, 2,550,797,
Mo-2839
0~2
- 29
2550,833, 2,550,860 and 2,550,862. These disclosures
also teach auxiliary agents and additives which may be
used in the production of polyurethanes.
The present invention also relates to the use
5 of the polyamines of the present lnvention for ~he
produc~ion of polyurethane(urea)s. They may be used,
for example, for the production of elastomers~ coatings
and threads and applied as solvent-free melts,
solutions, dispersions or mix~ures of reactive
10 components.
The polyamines of the present Lnvention may
also be used as coupling components for diazo dyes,
hardeners for epoxide and phenol resins and all other
known reactions of amines such ~s the formation of
15 amides and imides, etc.
The Examples which follow serve to illustrate
the present invention. Quantities given are to be
understood as parts by weight or percentages by weight
unless otherwise indicated.
EXAMPLES
Example 1
The isocyanate compound used in this F.xample
was an isocyanate prepolymer having an isocyanate
content of 3.65% which had been prepared by stirring a
25 mixture of polypropylene glycol having an OH number of
56 and tolylene-2,4-diisocyanate in an equivalent ratio
of NCO:OH = 2:1 at 80C for 3 hours.
A mixture of 1750 ml of dimethylformamide (DMF)
and 50 ml of water ~DMF/H2O = 33.2:1) was introduced
30 into the reaction vessel and heated to 90~C with
stirring. 500 g of the above-described isocyanate
prepolymer was added at this temperature in the course
of 20 minutes. Stirring was csntinued for 5 minu~es
after all the prepolymer had been added (evolution of
Mo-2839
~o~
- 30 -
C2 rapidly died down) and DMF and water were then
distilled off by application of a vacuum (ini~ially 19.5
mbar and later 0.13 mbar at 80 to 100C).
NH number (HC104): 31.1 mg KOH/g
xample 2
A mixture of 1750 ml of DMF, 50 ml of water and
1 g of sodium chloride was introduced into the reaction
vessel. The experiment was then carried out with the
same isocyanate prepolymer in the same amount and the product
10 worked up as described in Example 1. The NH number
(HC104) was found to be 31.3 mg KOH/g.
As Examples 1 and 2 illustrate, hydrolysis can
be carried out relatively successfully with mixtures of
DMF/H2O but the conversion rates are considerably lower
15 without catalyst than with the addition of (even small
quantities of) catalyst (see Example 9)O
Example 3 (Comparative)
A mixture of 1750 ml of DMF, 50 ml of water and
1 g of acetic acid was introduced into the reaction
20 ~ressel at 90C. The experiment was then carried out
with the same isocyanate prepolymer in the same amount
and the product worked up in the same way as in Example
1, a product havin~ an NH number (HC104) of only 28.4 mg
KOH/g was obtained.
25 Examples 4 to 6 (Comparative)
The isocyanate compound used in these Examples
was an isocyanate prepolymer which was identical to the
prepolymer from ExampLe 1 except that it had an
isocyanate content of only 3.3%.
A mixture of 1.75 1 of acetone or 1.75 1 of
dioxane or 1.75 1 of acetonitrile with 25 ml of water
and 0.1 g of sodium hydro~ide was introduced into the reaction
vessel with stirring at 90C or at the reflux temperature of acetone,
respectively acetonitrile, and using 500 g of the above-described
Mo-2839
~;~60
- 31 -
prepolymer, the experiment was carried out and the
product worked up as in Example 1.
NH numbers (HC104)
When acetone was used :27.9 mg KOH/g
5 When dioxane was used :6.85 mg KOH/g
when acetonitrile was used :26.9 mg KOH/g.
The conversion rates of NCO into NH2 were
unsatisfactory (i.e. low NH numbers) in spite of the use
of alkaline catalysts.
10 Example 7 (Comparative)
A mixture of 17SO ml of methyl ethyl ketone,
50 g of water and 0.2 g of sodium formate was introduced
into the reaction vessel at 90C. 500 g of the
isocyanate prepolymer from Example 1 were added within
15 20 minutes. After the reaction mixture had been worked
up as in Ex~mple 1, a product having an NH number
(HC104) of 31.5 mg KOH/g was obtained. The OH number
was distinctly lower than that obtained when solvents
according to the invention are used.
20 Example 8 (Comparative)
1 1 of methyl ethyl ketone, 15.2 g of
dimethylformamide, 30 ml of water and 1 g of sodium
formate were introduced into the reac~ion vessel at the
reflux temperature. 300 g of the isocyanate prepolymer
25 from Example 1 were added within 20 minutes. After the
reaction mixture had been worked up as in Example 1, a
product having an NH number (HC104) of 23.9 mg KOH/g was
obtained.
Examples 9-22
These Examples demonstrate the catalytic
properties of sodium hydroxide solution (NaOH).
Example 9
In this Example, a prepolymer having an
isocyanate content of 3.9% prepared by stirring for 3
Mo-2839
~260(~
- 32 -
hours a mixture of tolylene-2>4~diisocyanate and a
polyester of adipic acid, ethylene glycol and
butane-1,4-diol (molar ratio ethylene glycol:butanediol
= 7:3) with an OH number of 56 at an NCO/OH ratio of 2:1
5 was used.
A mixture of 5.5 1 of DMF, 125 ml of water
(DMF/water ratio = 41.7:1; 2.9 mol of water per
isocyanate equivalent) and 0.25 g of NaOH (OoOl wt. %
based on the isocyanate prepolymer) was introduced into
10 the reaction vessel and heated to 90C. 2.5 kg of the
polyether prepolymer described above which had been
heated to 70C were added within 45 minutes. The
product was worked up as in Example 1.
NH number (HC104) : 47.85 mg KOH/g
15 NH number (Ac~O/Py) : 47.9 mg KOH/g
(Py = pyridine)
S number (Ac20/Py) : 0.35 mg KOH/g
(S number = acid number)
TDA content (HPLC~ : 0.921% (HPLC = High Pressure
Liquid Chromatography)
DMF residual content(GC): 0.225 ~ (GC = Gas Chroma-
tography)
Example 10
A mixture, heated to 90C, of 1.75 1 of DME,
25 0.08 g of NaOH (0.016 wt. ~ based on the isocyanate pre-
polymer) and 50 ml of water (DMF/H20 ratio = 33.2:1;
6.375 mol of water per isocyanate equivalent) was intro-
duced into the reaction vessel. 500 g of the isocyanate
prepolymer from Example 1 having an isocyanate content
30 of 3.65% were added within one minute. The product was
worked up as in Example 1.
NH number (HC104) : 44.8 mg KOH/g
NH number (Ac20/Py) : 46.4 mg KOH/g
S number (Ac20/Py) : 0.1 mg KOH/g
Mo-2839
::IL26~0
- 33 -
Examples 11 and 12
A mixture of 1.1 1 of DMF, 0.05 g of NaOH
(O.01% by weight based on the isocyanate prepolymer) and
25 g of water (DMF/water ratio 41.7:1; 3.52 mol of water
5 per isocyanate equivalent) was introduced a~ 90C into
the reaction vessel. 500 g of the isocyanate prepolymer
from Example 4 containing 3.3~ NCO were added within 20
minutes. The product was worked up as in Example 1.
NH number (HCl04) : 47.4 mg KOH/g
10 NH number (Ac2O/Py): 47.6 mg XOH/g
S number (Ac2O/Py): 0.09 mg KOH/g
TDA content (HPLC) : 0.438
When 0.1 g of NaOH (0.02 wt. %, based on the
isocyanate prepolymer) was used ins~ead of 0.05 g of
15 NaOH under otherwise identical conditions and using
otherwise the same components, a product having an NH
number (HCl04) of 46.1 mg KOH/g was obtained.
Example 13
A mixture, heated to 90C7 of 1.1 l of DMF,
20 0.025 g of NaOH (0.005 wt. %, based on the isocyanate
prepolymer) and 25 g of water (DMF/water ratio = 41.7:1)
was introduced into the reaction vessel. 500 g of the
isocyanate prepolymer from Example 1 having an
isocyanate content of 3.6% (3,23 mol of water per
25 isocyanate equivalent) were added within 20 minutes.
The product was worked up as in Example 1.
NH number (HC104) : 46.7 mg KOH/g
Example 14
A mixture of 1.75 1 of ~MF, 0.01 g of NaOH
30 (0.002 wt. %, based on the isocyanate prepolymer) and
50 g of water tDMF/water ratio = 33.2:1) was introduced
into the reaction vessel and heated to 90C. 500 g of
the isocyanate prepolymer from Example l having an
isocyanate content of 3.6% (6.46 mol of water per NCO)
Mo-2839
- 34
were added within 20 minutes. The product was worked up
as in Example 1.
NH number (HC104) : 43.4 mg KOH/g
NH number (Ac20/Py) : 49.15 rng KOH/g
5 S number (Ac20/Py) : 0.1 mg KOH/g
Example 15
A mixture of 1.1 l of DMF, 0.025 g of NaOH and
25 g of water was introduced into the reaction vessel
and heated to 90C. 500 g o the isocyanate prepolymer
10 from Example 4 having an isocyanate content of 3.3% NCO
were added within one minute and the mixture was then
stirred ~or 20 m;nutes. The product was otherwise
worked up as in Example 1.
NH number (HCl04) : 42.6 mg KOH/g
15 Example 16
An isocyanate prepolymer having an isocyanate
content of 3.19% and obtained from a polyester with an
OH number of 50 and tolylene-2,4-diisocyanate in an
NCO/O~ ratio of 2:1 was used m this Example. me polyester used
20 was made from approximately equivalent a~unts o~ adipic acid and
hexane-1,6-diol and had an OH numb2r of 41.
A mixture of 4.4 1 of DMF 9 100 g of water and
0.2 g of NaOX was introduced into the reaction vessel
, and heated to 90C with stirring. 2 kg of the
25 above-mentioned isocyanate prepolymer ~at 60C) were
added with stirring within 45 minutes. The product was
worked up as in Example 1.
NX number (HC104) : 43.5 mg KOH/g
NH number (Ac20/Py) : 43.85 mg KOH/g
~0 S number (Ac20/Py) : 0.4 mg KOH/g
TDA content ~HPLC) : 0.81 %
Example 17
An isocyanate prepolymer having an isocyanate
content of 2.34% and obtained from a polyester and
Mo-2839
~oo~
- 35 -
tolylene-2,4-diisocyanate in an NCO/OH ratio of 2:1 was
used in this Example. The polyester was made from 1:1
adipic acid and diethylene glycol and had an OH number
of 41.
A mixture, heated to 90C, of 1.75 1 of DMF,
0.05 g of NaOH and 50 ml of wa~er was introduced into
the reaction vessel. 500 g of the above prepolymer were
added within 30 minutes with stirring. The product was
worked up as in Example 1.
10 NH number (HC10~) : 28.05 mg KOH/g
TDA content (HPLC) : 0.206 %
Example 18
An isocyanate prepolymer having an isocyanate
content of 3.4% and obtained from a polyether mixture
15 and tolylene-2,4-diisocyanate was used in this Example.
The polyether mixture had an OH number of 50 and a
functionality of 2.5 and was a 1:1 mixture of
trimethylol propane and a PO/EO polyether which had been
started on propylene glycol.
2Q A mixture, heated to 90C, of 3.5 1 of DMF, 0.1
g of NaOH and 100 ml of water was introduced into the
reaction vessel. 1000 g of the above-mentioned
prepolymer were added within 40 minutes wlth stirring.
The product was worked up as in Example 1.
25 NH number (HC104) : 44.3 mg KOH/g
NH number (Ac20/Py) : 43,5 mg KOH/g
S number (Ac20/Py~ : 0.3 mg KOH/g
TDA content (HPLC) : 0.087 %
Example 19
A prepolymer having an isocyanate content of
3.1% obtained by stirring for 3 hours at 80C
polytetramethylene glycol having an OH number of 56 and
tolylene-2,4-diisocyanate in an NCO/OH ratio of 2:1 was
used in this Example.
Mo-2839
o~
- 36 -
A mixture, heated to 90C, of 1.75 1 of DMF,
0.05 g of NaOH and 50 ml of water was introduced into
~he reaction vessel. 500 g of the above-mentioned
prepolymer were added within 20 minutes. The product
5 was worked up as in Example 1.
NH number (HC104) : 39.5 mg KOH/g
TDA content (HPLC) : 0.281 %
Example 20
A prepolymer with isocyanate content 2.8%
10 obtained by stirring for 4 hours at 80C (from an ester
with OH number 56 (as in Example 9~ and diphenylmethane-
4,4'-diisocyanate in an NCO/OH ratio of 2:1) was used in
this Example.
A mixture, heated to 90C, of 1.75 1 of DMF,
15 0.05 g of NaOH and 50 g of water was introduced into the
reaction vessel. A freshly prepared mixture of 500 g of
the above-mentioned prepolymer and 200 g of DMF was
added within 35 minutes. The product was worked up as
in Example 1.
20 NH number (HC104) : 31.4 mg KOH/g
NH number (Ac2O~Py) : 29.25 mg KOH/g
S number (Ac20/Py) : O.2 mg ROH/g
MDA-4,4' content (HPLC) : 1.48 %
Example 21
A prepolymer with isocyanate content 1.87Z
obtained by stirring for 4 hours at 80C from a
polyetherdiol with an OH number of 28 (obtained by
blockwise addition of 80~ propylene oxide followed by
2~ ethylene oxide to propylene glycol and using an NCO/OH ratio of 2:1)
30 and 2,4-tolylene diisocyanate was used in this E~ample.
A mixture, heated to 90C, of 1.75 1 of DMF,
0.05 g of NaOH and 50 ml of water was introduced into
the reaction vessel. 500 g of the above-described
prepolymer were added in 30 minutes. The product was
35 worked up as in Example 1.
Mo-2839
~ 2
- 37 -
NH number (HC104) : ~3.7 mg/KOH/g
Example 22
An NCO:OH = 2:1 prepolymer obtained by stirring
for three hours at 80C of a polyethertriol with OH
5 number 28 obtained by the addition of 87 wt. D~ propylene
oxide followed by 13 wt. DZ ethylene oxide to trimethylol-
propane and 2,4-tolylene diisocyanate having an isocyanate
content of 1.8% was used in this Example.
A mixture of 1.75 1 of DMF, 0.05 g of NaOH and
10 50 ml of water (12.9 mol of water per isocyanate
equivalent; DMF/H20 ratio = 33. 2 :1 ) was introduced into
the reaction vessel. 500 g of the isocyanate prepolymer
described ahove were added in 30 minutes. The product
was worked up as in Examp]e 1.
NH number (HC104 ) : 25 .15 mg KOH/g
NH number (Ac20/Py) : 24 . O mg KOH/g
S number (Ac20/Py) : O. 2 mg KOH/g
Examples 23-25
The efficient action of sodium aluminate is
20 demonstrated in these Examples.
Example 23
A mixture of 1750 ml of DMF, 50 g of water and
O . l g of sodium aluminate was introduced into the
reaction vessel at 90C. 50Q g of the isocyanate
25 prepolymer from Example l having an isocyanate content
of 3.65Z (ratio H20:NCO about 6.4:1) were added with
stirring. The product was prepared and worked up as in
Example 1.
NH number (HCl04) : 51.6 mg KOH/g
30 NH number (Ac20/Py) : 51.5 mg KOH/g
S number (Ac20/Py) : 0.1 mg KOH/g
TDA content (HPLC) : 0.81 D~
Mo-2839
o~
- 38 -
Example 24
A mixture, heated to 90C, of llOO g of DMF,
25 g of water and 0.01 g of sodium aluminate was
introduced into the reaction vessel. 500 g of the
5 isocyanate prepolymer from Examp:le 4 having an
isocyanate content of 3.3% (ratio H20:NCO =
approximately 3.5:1) were added within 20 minutes with
stirring. The product was prepared and worked up as in
Example 1.
lO NH number (HC104) : 47.15 mg KOH/g
Example 25
A mixture, heated to 90C, of llOO g of DMF,
25 g of water and 0.05 g of sodium aluminate was
introduced into the reaction vessel. 500 g of an
15 isocyanate prepolymer prepared by the same method as the
isocyanate prepolymer from Example 1 but having an
isocyanate content of 3.2~ were added with stirring
(ratio H20:NCO = 3.65:1). The product was prepared and
worked up as in Example l.
20 NH number (HC104) : 41.7 mg KOH/g
Example 26
A mixture, heated to 90C, of 1.75 1 of DMF,
SO g of water and 2.5 g of KHC03 (0.5 wt. %, based on
the isocyanate prepolymer; DMF/water ratio by weight =
25 33.2:1; 7.05 mol of water per NCO) was introduced into
the reaction vessel. 500 g of the isocyanate prepolymer
from Example 4 havi.ng an isocyanate content of 3.3% were
added within 20 minutes. The product was worked up as
in Example l.
30 NH number (HC104) : 47.3 mg KOH/g
Examples 27-28
These Examples demonstrate that the use of
larger quantities of water lead to poorer results, i.e.
lower NH numbers due to lower NCO/NH2 conversion rates.
Mo-2839
.~2~VO~
- 39 -
Example 27
A mixture, heated to 90C, of 1.5 1 of DMF, 250
ml of water t32.32 mol of water/NCO equivalent;
DMF/water ratio = 5.9:1) and 0.05 g of KHCO3 (0.01 wt.
5 ~, based on the prepolymer) was introduced into the
reaction vessel. 500 g of the isocyanate prepolymer
from Example 1 having an isocyanate content of 3.6% were
added within 20 minutes. The product was worked up as
in Example 1.
10 NH number ~HC104) : 37.8 mg KOH/g
NH number (Ac2O/Py) : 38.95 mg KOH/g
S number (Ac2O/Py) : 0.1 mg KOH/g
Example 28
A mixture, heated to 90C, of 1.5 1 of DMF9 250
15 ml of water (DMF/H2O ratio = 5.9:1) and 0.05 g of sodium
forma~e was introduced into the reaction vessel. 500 g
of the prepolymer from Example 4 having an isocyanate
content of 3.3% were added within 20 minutes. The
product was worked up as in Example 1.
20 NH number (HC104) : 33.7 mg KOH/g
Example 29
A mixture, heated to 90C, of 1.75 1 of DMF,
50 g of water and 0.~4 g of sodium formate (HCO2Na) was
introduced into ~he reaction vessel. 500 g of the
25 isocyanate prepolymer from Example 1 were added with
stirring and the reaction was continued and the product
worked up as described in Example 1.
N~ number (HC104) : 50.5 mg KOH/g
NH number tAc2O/Py) : 48.4 mg KOH/g
30 S number (Ac2O/Py) : 0.1 mg KOH/g
Examples 30 to 40
Isocyanate prepolymers obtained by stirring for
4 hours at 80C of a mixture of tolylene-2,4-diiso-
Mo-2839
~6
- 4~) -
cyanate and a polyoxypropylene g:Lycol with OH number 32
which had been started on trimethylolpropane were used
in these Examples. A product having an isocyanate
content of 2,1Z was used in Examples 30 to 33. A
5 product with an isocyanate content of 2.3% was used in
Examples 34 to 36, 38 and 39 and one having an
isocyanate content of 2.2~ was used in Examples 37 and
40.
Example 30
A mixture, heated to 90C, of 1.1 1 of DMF, 25
ml of water and 0.025 g of NaOH was introduced into the
reaction vessel with stirrin~. 500 g of a prepolymer
described above having an isocyanate content of 2.1% was
added at this reaction temperature with stlrring and the
15 reaction was then continued and the product worked up as
in Example l.
NH number (HC104) : 30.8 mg KOH/g
NH number (Ac20/Py) : 34,0 mg KOH/g
S number (Ac20/Py) : 0.05 mg KOH/g
20 Example 31
A mixture, heated to 90C, of 1.1 1 of DMF,
25 ml of water and 0.01 g of NaOH was introduced into
the reaction vessel with stirring, 500 g of the
isocyanate prepolymer from Example 30 were added at this
25 reaction temperature with stirring and then reacted and
worked up as in Example 1.
NH number (HC104) : 29.8 mg KOH/g
NH number ~Ac20/Py) : 33.5 mg KOH/g
S n~mber (Ac20/Py) : O.05 mg KOH/g
30 Example 32
A mixture, heated to 90CI of 1.1 1 of DMF,
25 ml of water and 0.005 g of NaOH was introduced into
the reaction vessel with stirring. 500 g of the
isocyanate prepolymer from Example 30 were added at this
Mo-2839
6~
reaction temperature and reacted and worked up as in
Example l.
NH number (HC104) : 31.1 mg KOH/g
NH number (Ac2O/Py) : 32.1 mg KOH/g
5 S number (Ac2O/Py) : 0.05 mg KOH/g
Example 33
A mixture, heated to 90C9 of 1.1 1 of DMF,
25 ml of water and 0.0025 g of NaOH (0.0005 wt. %, based
on the prepolymer) was introduced into the reaction
10 vessel with stirring. 500 g of the isocyanate
prepolymer from Example 30 were added at this
temperature with stirring and reacted and worked up as
in Example 1.
NH number (HCl04) : 29.4 mg KOH/g
15 NH number (Ac2O/Py) : 28.6 mg KOH/g
S number (Ac2O/Py) : 0.05 mg KOH/g
Virtually the same results were obtained when
0.0025 g of ~OH was used.
Example_34
A mixture, heated to 90C, of 1.1 1 of DMF, 25
ml of water and 0.005 g of KOH was introduced into the
reaction vessel with stirring. 500 g of a prepolymer
similar to that used in Example 30 and described above
having an isocyanate content of 2.3% were added with
25 stirring at 90C and reacted and worked up as in Example
1.
NH num~er (HCl04) : 29.2 mg KOH/g
Example 35
A mixture of 1.1 1 of DMF, 25 ml of water and
30 0.0025 g of NaOH was introduced into the reaction vessel
with stirring at 45C, 500 g of the same isocyanate
prepolymer as was used in Example 34 were added at this
reaction temperature with stirring but stirring was then
continued for 20 minutes (end of evolution of CO2). The
35 product was worked up as in Example 1.
Mo-2839
~ ~ 6
- 42 -
Fxample 36
A mixture of 1.1 1 of DMF, 25 ml of water and
0.1 g of NaOH was introduced into the reaction vessel at
45C with stirring. 500 g of the same isocyanate
5 prepolymer as was used in Example 34 were added at this
reaction temperature with stirring. Stirring was then
continued for 25 minutes during which one sample was
removed after 5 minutes. Both samples were worked up as
in Example 1.
10 NH number (HCl04 after 5 min): 29.4 mg KOH/g
NH number (HC104 after 25 min): 29.0 mg KOH/g
This shows that even at 45C the reaction was completed
5 minutes after all the reactant had been added and that
more prolonged stirring did not provide any advantages.
15 Example 37
A mixture of 1.1 1 of DMF, 25 ml of water and
0.05 g of KOH was introduced into the reaction vessel at
45C with stirring. 500 g of an isocyanate prepolymer
similar to that described in Example 30 above but having
20 an isocyanate content of 2.2Z were added at this
temperature with stirring. Subsequent treatment of the
reaction mixture and working up were the same as in
Example 1.
NH number (HC104) : 29.0 mg KOH/g
25 Example 38
A mixture of 1.1 1 of DMF and 25 ml o water
was introduced into the reaction vessel at 90C with
stirring. 500 g of the isocyanate prepolymer from
Example 34 were added at this reaction temperature with
30 stirring. The product was worked up as in Example 1.
NH number (HC104) : 17.5 mg KOH/g
When 0.2 g of l/lON NaOH were added to this
reaction mixture after all the isocyanate prepolymer had
been added and the mixture was then stirred at 90C for
Mo-2839
~6~0~L~
- 43 -
45 minutes, the product obtained after the reaction
mixture was worked up as in Example 1 and had an NH
number of 17.8 mg KOH/g (HC10~ method). This showed
that even without a catalyst, the reaction was completed
5 within 5 minutes after all of the isocyanate prepolymer
had been added.
Example 39
A mixture of 1.1 1 of DMF and 25 ml of water
was introduced into the reaction vessel with stirring at
10 a reaction temperature of 137C (reflux). 500 g of the
isocyanate prepolymer from Example 34 were added within
27 minutes. The reaction temperature fell to 130C
(bath temperature 160 - 180C) on addition of the
isocyanate prepolymer and reflux died down.
When the reaction mixture was worked up after a
further 5 minu~es of stirring under reflux, a product
having an NH number (HC104) of 20.7 mg KOH/g was
obtained.
When the reaction mixture was worked up under
20 reflux after 30 minutes of stirring, a product having an
NH number (HC104) of 21.3 mg KOH/g was obtained.
This shows that even without catalyst and at
this temperature the reaction was completed within 5
minutes after all the isocyanate prepolymer had been
25 added.
Examples 38 and 39 also demonstrate that
although the product obtained without the aid of a
catalyst is superior to one prepared according to DE
3,223,398 without a catalyst, it had a high degree of
30 prelengthening (urea formation).
Example 40 (Comparison Example to Example 38)
A mixture of 1.1 1 of DMF and 300 ml of water
was introduced into the reaction vessel and heated to
90C with stirring. 500 g of the isocyanate prepolymer
Mo-2839
2 ~
_ ~4 _
from Example 37 were added within 20 minutes with
stirring. A gel-like polymer then separated which would
not dissolve even in pure DMF or in acetic acid. When
attempts were made to determine an NH number of the
5 insoluble material, the result obtained was< 2 mg KOH/g
as the NH number.
This experiment demonstrates that the
water/solvent tor water/DMF) ratios used in DE 3,223,398
and 3,223,397 give less favorable results than those
10 obtained in the process of the present invention. This
means that the product obtained by the prior art process
is virtually unusable whereas the process according to
the invention provides useful liquid and soluble
products with respectable NCO/NH2 conversion rates and
15 considerable NH numbers even when carried out in a
manner which is not preferred.
Example 41
616 ml of DMF and 14 ml of H20 were introduced
into a 1.3 1 autoclave and heated to 150C. 280 g of
20 the isocyanate prepolymer used in Example 37 were then
added with stirring within 5 minutes, using a dosing
pump. The temperature ~f the isocyanate prepolymer was
50C. Stirring was then continued for a further 5
minutes at 150C and the reaction mixture was cooled,
25 the pressure released and the solvent distilled off as
in Example 1. A brown material having the following
data was obtained:
NH number (HC104): 28.9 mg KOH/g
~H number (Ac20/Py): 27.1 mg KOH/g
30 S number: 0.05 mg KOH/g
Molar masses: 3825, theoretical 3851 (determined by
vapor pressure osmometry)
TDA content: 0.288 wt. %
Mo-2839
.
~L~6001~
- 45 -
Example 42 (Comparati~Te)
600 ml of water were heated to 150C in a 1.3 1
autoclave, and 300 g of the isocyanate prepolymer from
Example 37 heated to 50C were added within 10 minutes.
5 Stirring was continued for a further 5 minutes at lS0C
and the reaction mixture was then cooled, the pressure
released and the water decanted from the product
obtained. The product was a viscous rubber but was
still partly soluble in a DMF/ethanol mixture at 80C.
The NH number of the part that was still
soluble ~after removal of the solvent by distillation)
was 11.1 mg KO~/g (HC104).
(Comparative)
Example 42 was repeated with the exceptlon that
15 0.06 g of KOH were added to the water. The product
obtained after working up was a swelled material
completely insoluble in DMF. No NH number could be
de~ermined.
~ le 44
20 a) Preparation of prepolymer
1218 g of toluylene diisocyanate (7 mol) were
heated to 60C. 90 ~ of butane-1,4 diol were added
within 40 minutes. The reaction product precipitated
towards the end of the reaction. Stirring was then
25 continued for one hour at 60C. The pasty mixture was
diluted with 2 1 of cyclohexane at 23C and suction
filtered, washed with cyclohexane and petroleum ether
and dried in a vacuum drying cupboard at 40C. The
product melted at 130 to 131C and had an isocyanate
30 content of 19.0% (the calculated isocyanate content for
a 2:1 adduct is 19.2%).
b) Preparation of polyamine
A mix~ure of 3256 ml of DMF, 0.15 g of KOH and
74 ml of water was introduced into the reaction vessel.
Mo-2839
- 46 -
A suspension of 310 g of the above-mentioned isocyanate
prepolymer in 600 ml of DMF was added with stirring at
90C within 20 minutes. 31 1 of CO2 were found ~o
evolve (theoretical 31.4 1). The solvent was then to a
5 large extent distilled off and the product was
precipitated from the liquid residue by means of a 10:1
mixture of water and methanol. The product was suction
filtered, washed with water and dried.
NH number (Ac2O/Py): 274 mg KOH/g (Th.: 288)
10 Acid number (Ac2O/Py): 0.4 mg KOH/g
Molar mass (vapor pressure osmometry): 395-400 (Th.:378)
TDA value (HPLC): 0.352%
NH number (HC104): 264 mg KOH/g; m.pt.: 168-169C.
Example 45
A mixture of 1750 ml of dimethylformamide~ 30
ml of water and 0.01 g of potassium octoate ~0.002 wt. %
based on the isocyanate prepolymer) was introduced into
the reaction vessel. The mixture was heated to 90C.
500 g of the isocyanate prepolymer from Example 9 heated
20 to 70DC, were added within 20 minutes and worked up as
described in that Example. The polyamine had an NH
number (Ac2O/Py) of 47.95 mg KOH/g.
Mo-2839
